DESCRIPTION: This proposal is concerned with the development of spatial coding abilities in the first few years of life. Such abilities are important for wayfinding and remembering location. To investigate these abilities, four experiments are proposed in which children between 1 and 3 years of age are required to locate an object that they have just witnessed being hidden in a sandbox. The goals of these experiments are to: 1) test the generality and robustness of young children s use of hierarchical spatial coding across differently shaped environment; 2) determine whether the hierarchical organization model is applicable for the maintenance of spatial orientation during movement through space; and 3) examine children's use of spatial landmarks to maintain spatial orientation during movement.